Electrochemical Capacitors

The first model for the distribution of ions near the surface of a metal electrode was devised by Helmholtz in 1874. He envisaged two parallel sheets of charges of opposite sign located one on the metal surface and the other on the solution side, a few nanometers away, exactly as in the case of a parallel plate capacitor. The rigidity of such a model was allowed for by Gouy and Chapman inde pendently, by considering that ions in solution are subject to thermal motion so that their distribution from the metal surface turns out diffuse. Stern recognized that ions in solution do not behave as point charges as in the Gouy-Chapman treatment, and let the center of the ion charges reside at some distance from the metal surface while the distribution was still governed by the Gouy-Chapman view. Finally, in 1947, D. C. Grahame transferred the knowledge of the struc ture of electrolyte solutions into the model of a metal/solution interface, by en visaging different planes of closest approach to the electrode surface depending on whether an ion is solvated or interacts directly with the solid wall. Thus, the Gouy-Chapman-Stern-Grahame model of the so-called electrical double layer was born, a model that is still qualitatively accepted, although theoreti cians have introduced a number of new parameters of which people were not aware 50 years ago.

Electrochemical capacitors are being increasingly introduced in energy storage devices, for example, in automobiles, renewable energies, and mobile terminals. This book includes five high-quality papers that can lead to technological developments in electrochemical capacitors. The first paper describes the effect of the milling degree of activated carbon particles used in the electrodes on the supercapacitive performance of an electric double-layer capacitor. The second, fourth, and fifth papers describe novel electrode materials that have the potential to enhance the performance of next-generation electrochemical capacitors. Nickel molybdate/reduced graphene oxide nanocomposite, copper-decorated carbon nanotubes, and nickel hydroxide/activated carbon composite are tested, and are shown to be promising candidates for next-generation electrochemical capacitors. The third paper reports the hybrid utilization of electrochemical capacitors with other types of energy devices (photovoltaics, fuel cells, and batteries) in a DC microgrid, which ensures wider applications of electrochemical capacitors in the near future. The knowledge and experience in this book are beneficial in manufacturing and utilizing electrochemical capacitors. Cutting-edge knowledge related to novel electrode nano-materials is also helpful to design next-generation electrochemical capacitors. This book delivers useful information to specialists involved in energy storage technologies.

Electrochemical capacitors are most important for the development of future energy storage systems and sustainable power sources. New superior hybrid supercapacitors are based on binary and ternary thin film nanocomposites involving carbon, metal oxides and polymeric materials. The synthesis of materials and fabrication of electrodes for supercapacitor applications is discussed in detail. The book also presents the fundamental theory and a thorough literature review of supercapacitors. Energy Storage, Electrochemical Capacitors, Nanocomposites, Hybrid Supercapacitors, Carbon/Metal Oxide Composites, Metal Oxides/Hydroxides Composites, Polymer Type Capacitors, Nanoscience, Hydrothermal Synthesis, Graphene-based Composites, Ultrasonic Assisted Synthesis

Electrochemical capacitors or supercapacitors offer a number of advantages over batteries; they are more safe and reliable, charge quicker, have an indefinite lifespan, exhibit a high power density and a wide range of working temperature. Supercapacitors demonstrate an extraordinary potential in both consumer electronics and large-sized energy storage applications, e.g. in communications, transportation, aviation, and power industries. The book explores recent developments in the area of composite applications for supercapacitor electrodes based von conducting polymers, graphene, biomass, or carbonaceous quantum dots. Synthesis strategies of composite materials and electrode preparation methods are discussed in detail. Electrochemical Capacitors, Supercapacitors, Energy Storage, Supercapacitor Electrodes, Conducting Polymer Composites, Graphene-based Composites, Biomass-based Capacitors, Carbonaceous Quantum Dot Composites, Sol-Gel Synthesis, Sonochemical Synthesis, Polyaniline-Zirconia Nanofibers

Electrochemical capacitors in part or in whole on the electrical double later at electrode interfaces have found application in a variety of energy storage applications. Paper for the symposium are solicited that cover all fundamental and practical aspects of ultracapacitors, supercapacitors, and similar electrochemical energy conversion devices, including: 1) double layer and/or pseudo-capacitance of carbons, conducting polymers, and advanced inorganic materials, 2) synthesis and characterization of high surface area materials for electrochemical capacitors, 3) development and optimization of practical ultra- and super-capacitor components, including current collectors, electrodes, electrolytes, separators and packaging, 4) performance of new device designs and construction using symmetric and asymmetric electrode constructions, 5) mathematical models for performance characterization, 6) comparison of energy, power, and lifetime characteristics of hybrid fuel cell and battery power sources utilizing electrochemical capacitors. Keynote speakers will present tutorials covering recent advances and future directions for electrochemical capacitor technology.